The flotation method is used in many fields of engineering, including that of waste-water purification. The flotation method however was not useful for removing emulsified or suspended solids from aqueous emulsions, dispersions and colloidal solutions.
The generation of large quantities of very small gas bubbles by means of electrolysis is also known, and is described, for instance in German Pat. No. 1,203,702. The very small dimensions of the gas bubbles generated by electrolysis enable the flotation method to be used for aqueous emulsions, dispersions and colloidal solutions. To optimize the results of this flotation method, which is effected substantially in the liquid column above the lowermost, relatively coarse-mesh electrode, both chemicals and a constant supply of energy are required. Moreover, that method necessitates relatively long treating times of 10-15 minutes.
The object of the invention is to reduce the period of time required for treatment to result in the electroflotation of emulsions, dispersions or colloidal solutions, to achieve a considerable saving of energy cost, and to eliminate the use of flotation chemicals. Another object is to reduce the size of the necessary device while maintaining the same flotation capacity in the smaller device.